HCI_COMM_Protocol_t definition

Hi,

My customer is using CC2564B and MSP430F5438A.

According to below E2E item (now read only), using cpHCILL_RTS_CTS or cpHCILL for HCI_COMM_Protocol enables eHCILL protocol.
https://e2e.ti.com/support/wireless_connectivity/bluetooth_cc256x/int_bluetooth_cc256x/f/963/t/521490

The definition is done inside
\CC256x MSP430 Bluetopia SDK\v1.5 R2\MSP430_Experimentor\Bluetopia\include\HCICommT.h

typedef enum

{

   cpUART,

   cpUART_RTS_CTS,

   cpBCSP,

   cpBCSP_Muzzled,

   cpH4DS,

   cpH4DS_RTS_CTS,

   cpHCILL,

   cpHCILL_RTS_CTS,

   cp3Wire,

   cp3Wire_RTS_CTS,

   cpSIBS,

   cpSIBS_RTS_CTS

} HCI_COMM_Protocol_t;

Customer is asking what are exact differences between cpHCILL_RTS_CTS and cpHCILL.
And what are other definitions ? Is there specification explains them ?

Thanks and regards,
Koichiro